Robert Watt, first-person narrator of Wallace's unsettling, uneven debut novel, is a Scottish doctor who, upon retirement, recalls his wartime service as a 24-year-old newly accredited medic sent out into the chaos of postwar Europe. His job was to identify the origins of a baffling epidemic at two refugee camps--one outside of Berlin and the other on the Polish-Ukrainian border--and he makes it clear that something awful happened that has haunted him for the rest of his life and even invalidated his career. ""I cannot talk of my career in medicine because I am, and always have been, a fraud."" His secret past gradually comes to light through a series of flashbacks--a lengthy process, since the primary narrative alternates with another: a ""paper"" on the true story behind the Pied Piper of Hamelin. This document is reputedly written by Arthur Lee, Robert's colleague at both camps, a man deranged yet enlightened by the loss in the Blitz of his wife and children. Presumably, Wallace decided to juxtapose these two narratives because both bear witness to how blind and ultimately evil humans can be when faced with situations of anarchy and chaos, but the fit is forced. Neither narrative is strong enough to support the portentousness of its themes--""the devils have taken over, the ones from within""--and the invented horrors feel a bit redundant in a novel that takes place right after the Holocaust. This failure is particularly disappointing as Wallace can write: his na ve young Scot has a convincing voice, and it is easy to believe in his postadolescent fumblings and blindness. Given a decent plot, this new author could go far. (May)